Precision at $0.5\text{ pt}$: Engineering Micro-Text in Metallic Hot-Foil Stamps
Micro-printing—text printed so small that it requires a magnifying glass or loupe to read—is a standard security feature on banknotes and passports. Traditionally, micro-text was limited to offset lithography or high-resolution ink printing. Stamping micro-text in metallic hot-foil, however, presents an extreme physical challenge. Molten foil tends to bridge across micro-cavities, filling in the loops […]